The forum can be found here:

https://theme-fusion.com/forums/topic/not-able-to-edit-anymore-after-update-wordpress-4-1/#post-352568

Apparently what is needed is to
-update to latest version of Avada
-update fusion core plugin

For fusion core plugin change a line:

change the value of the line 1126 in file: wp-content/plugins/fusion-core/admin/page-builder/assets/css/application.css from:

z-index: 1001 !important;

to

z-index: 999 !important;